Genetic polymorphisms of VKORC1, CYP2C9, CYP4F2 in Bai, Tibetan Chinese

Background: VKORC1, CYP2C9 and CYP4F2 are three critical genes associated with inter-individual variation of warfarin dose. Many dosing algorithms containing these gene polymorphisms and demographic characteristics have been set up for better use of warfarin. However, with distinct gene mutation frequencies among different ethnics, dosing algorithms differ greatly. For Chinese, related research just concentrate on Han Chinese, ignoring other Chinese ethnicities. This study aims to detect the popular polymorphisms in these three critical genes in Bai, Tibetan Chinese, to start the exploration of better use of warfarin in Chinese minorities. Methods: PCR-based methods were used to analyze VKORC1 3673G > A, CYP2C9(star)3, CYP4F2 rs2108622 C > T in Han, Bai and Tibetan Chinese. Results: The differences among the mutation frequencies of the studied genes in three ethnicities were not statistically significant. The frequency of A-allele of VKORC1 3673G > A was 92.8%, 90.2%, 90.8% in Bai, Tibetan, Han Chinese, respectively. The frequency of (star)3-allele in CYP2C9(star)3 was low in Bai (4.5%), Tibetan (2.8%) and Han Chinese (4.6%). Approximately one fourth of each ethnic had the mutant T-allele of CYP4F2 rs108622. However, Bai Chinese got statistically higher A-allele frequency of VKORC1 3673G > A than previously studied Han Chinese did. Conclusions: Bai Chinese got significant higher A-allele frequency of VKORC1 3673G > A.